\begin{tikzpicture}
	\tkzDefPoints{0/0/B, 3/0/C, 0.8/1.5/A, 2.2/1.5/D}
    \tkzDrawPolygon(A,B,C,D)
    \tkzLabelPoints[left](A,B)
    \tkzLabelPoints[right](D,C)

    \tkzDefLine[parallel=through D](A,B)  \tkzGetPoint{e}
    \tkzInterLL(D,e)(B,C)  \tkzGetPoint{E}
    \tkzDrawSegment[dashed](D,E)
    \extkzLabelAngel[0.3](C,E,D){$1$}
    \tkzLabelPoints[below](E)
\end{tikzpicture}

